The reason -- I don't really want to go into the details as to how we built our own weapons and our own races and so on. At least if you're already an owner of this book (or want to pick it up for $10 on DriveThruRPG), you can follow on your own and come up with your own scenarios & tactics.
Initial Framework
We'll need to establish a squad comprised of several characters (therefore, character sheets are needed), and put in the general logic of the build of the characters (alien race and various MOS packages, plus extras) and the composition of the team in terms of 'roles'.
Then we go into the three components of each scenario -- the opposition, the terrain, and of course the equipment you've been assigned! Now there's a standard loadout (we're going for a military group that gets standard equipment), but can request for specialized equipment as well, depending on organizational pull of the team's leadership and the nature of mission itself.
And then we'll talk about how the combination of these might play out in a given situation; how to make decision making and running combat smoother without sacrificing the combat options, and so on.